The invention relates to an installation for storing rod stock and for the automatic, program-controlled supplying of a severing machine with this stock. Such installations are composed of a plurality of shelving units arranged side by side transversely of the longitudinal direction of the stock, having shelving compartments arranged one above the other on at least one side and formed of carrier arms, with stock of one material and one cross section being stored in each compartment, a gantry crane with a crane bridge movable upwardly and downwardly over the shelving units, transversely of the shelving gangways and in the shelving gangways, provided with means for taking up the stock from the shelving compartments, for transporting it and for replacing it in the shelving compartments, and a rollway occupying the position of one shelving compartment, drivable in both directions of rotation and essentially forming a horizontal carrier, for feeding stock laid upon it to the severing machine and for bringing back the material from the severing machine after it has been worked therein, the severing machine being arranged with respect to its longitudinal direction, outside the zone occupied by the shelving units and the gantry crane.
Known installations of this kind operate completely automatically with the aid of their program control system, which is controlled for example by the insertion of order cards which indicate the material, stock cross section and number of pieces to be cut. On the basis of such an order card, the gantry crane picks up the stock to be worked and lays it upon the rollway, whence it is then fed to the severing machine. After working, the stock is brought back again into the storage zone by the rollway and then returned to its original place by the gantry crane.
This sequence of movement requires a considerable time before the worked stock has been brought back to its place and the stock to be worked next has been brought to the rollway.
To deal with this problem it has in fact already become known to keep one or two compartments free in the vicinity of the rollway for the interim storage of stock so that then the stock to be worked next can be brought into one of those compartments while the previously selected stock is still being worked. Then the worked stock can be brought by the gantry crane into the other free compartment and the stock to be worked next can be brought on to the rollway. Now during the next working phase there is sufficient time for the gantry crane to store away the already worked stock and to bring forward the stock which is now next to be worked.
However even this procedure entails a lengthy expenditure of time for the change of stock, which is taken away from productive working time. This loss may still be tolerable if equipment of the known kind is being used for severing large numbers of pieces from one stock type. Then the stock change time is unimportant in comparison with the working time. If, however, it is intended to operate an installation which is to sever smaller numbers of pieces from different stocks then the stock change time gains decisive importance and thus has a considerable influence upon the economic use of the equipment.